69 Dart Swinger Wheels /Tires

68 Coronet RT said
I have a 68 Dart GTS and does anyone know if a 255/70/15 using a 15 X 7 rim with a 4.25 backspacing with stock suspension work or will it be to close for comfort

It will be too tall, unless you put a spacer between front spring hanger and frame. That tire is 29" tall and will hit front of wheel opening. Im currently running 235 70r15 and have about 1/2" of space using an 1/8" shim.